China is now at war. It is not invading armies that are claiming its territory, but expanding deserts. Old deserts are advancing and new ones are forming, like guerrilla forces striking unexpectedly, forcing Beijing to fight on several fronts. And worse, the growing deserts are gaining momentum, occupying an ever-larger piece of China's territory each year.

Desert expansion has accelerated with each successive decade since 1950. China's Environmental Protection Agency reports that the Gobi Desert expanded by 52,400 square kilometers (20,240 square miles) from 1994 to 1999, an area half the size of Pennsylvania. With the advancing Gobi now within 150 miles of Beijing, China's leaders are beginning to sense the gravity of the situation.

Overplowing and overgrazing are converging to create a dust bowl of historic dimensions. With little vegetation remaining in parts of northern and western China, the strong winds of late winter and early spring can remove literally millions of tons of topsoil in a single day—soil that can take centuries to replace.

For the outside world, it is these dust storms that draw attention to the deserts that are forming in China. On April 12, 2002, for instance, South Korea was engulfed by a huge dust storm from China that left people in Seoul literally gasping for breath. Schools were closed, airline flights were cancelled, and clinics were overrun with patients having difficulty breathing. Retail sales fell. Koreans have come to dread the arrival of what they now call "the fifth season"—the dust storms of late winter and early spring. Japan also suffers from dust storms originating in China. Although not as directly exposed as Koreans are, the Japanese complain about the dust and the brown rain that streaks their windshields and windows.

Each year, residents of eastern Chinese cities such as Beijing and Tianjin hunker down as the dust storms begin. In addition to having problems with breathing and the dust that stings the eyes, people are constantly working to keep dust out of homes and to clean doorways and sidewalks of dust and sand. Farmers and herders, whose livelihoods are blowing away, are paying an even heavier price.

A report by a U.S. embassy official in May 2001 after a visit to Xilingol Prefecture in Inner Mongolia (Nei Monggol) notes that although 97 percent of the region is officially classified as grasslands, a third of the terrain now appears to be desert. The report says the prefecture's livestock population climbed from 2 million as recently as 1977 to 18 million in 2000. A Chinese scientist doing grassland research in the prefecture says that if recent desertification trends continue, Xilingol will be uninhabitable in 15 years.

A more recent U.S. embassy report entitled "Desert Mergers and Acquisitions" says satellite images show two deserts in north-central China expanding and merging to form a single, larger desert overlapping Inner Mongolia and Gansu provinces. To the west in Xinjiang Province, two even larger deserts—the Taklimakan and Kumtag—are also heading for a merger. Highways there are regularly inundated by sand dunes.

In the deteriorating relationship between the global economy and the earth's ecosystem, China is on the leading edge. A human population of 1.3 billion and a livestock population of just over 400 million are weighing heavily on the land. Huge flocks of sheep and goats in the northwest are stripping the land of its protective vegetation, creating a dust bowl on a scale not seen before. Northwestern China is on the verge of a massive ecological meltdown.

While overplowing is now being partly remedied by paying farmers to plant their grainland in trees, overgrazing continues largely unabated. China's cattle, sheep, and goat population tripled from 1950 to 2002. The United States, a country with comparable grazing capacity, has 97 million cattle. China has 106 million. But for sheep and goats, the figures are 8 million versus 298 million. Concentrated in the western and northern provinces, sheep and goats are destroying the land's protective vegetation. The wind then does the rest, removing the soil and converting productive rangeland into desert. (See data.)

The fallout from the dust storms is social as well as economic. Millions of rural Chinese may be uprooted and forced to migrate eastward as the drifting sand covers their land. Expanding deserts are driving villagers from their homes in Gansu, Inner Mongolia, and Ningxia provinces. An Asian Development Bank assessment of desertification in Gansu Province reports that 4,000 villages risk being overrun by drifting sands.

The U.S. Dust Bowl of the 1930s forced some 2.5 million "Okies" and other refugees to leave the land, many of them heading from Oklahoma, Texas, and Kansas to California. But the dust bowl forming in China is much larger, and during the 1930s the U.S. population was only 150 million—compared with 1.3 billion in China today. Whereas the U.S. migration was measured in the millions, China's may eventually measure in the tens of millions. And as a U.S. embassy report entitled "The Grapes of Wrath in Inner Mongolia" noted, "unfortunately, China's twenty-first century 'Okies' have no California to escape to—at least not in China."

Planting marginal cropland in trees helps correct some of the mistakes of overplowing, but it does not deal with the overgrazing issue. Arresting desertification may depend more on grass than trees—on both permitting existing grasses to recover and planting grass in denuded areas. Beijing is trying to arrest the spread of deserts by encouraging pastoralists to reduce their flocks of sheep and goats by 40 percent, but in communities where wealth is measured not in income but in the number of livestock owned and where most families are living under the poverty line, such cuts are not easy. Some local governments are requiring stall-feeding of livestock with forage gathered by hand, hoping that this confinement measure will permit grasslands to recover.

China is taking some of the right steps to halt the advancing desert, but it has a long way to go to reduce livestock numbers to a sustainable level. At this point, there is no plan in place or on the drawing board that will halt the advancing deserts.

The entire world has a stake in China's winning the war with the advancing deserts given its economic leadership role. But winning will not be easy. Qu Geping, the Chairman of the Environment and Resources Committee of the National People's Congress, estimates that the remediation of land in the areas where it is technically feasible would cost $28.3 billion. Halting the advancing deserts will require a massive commitment of financial and human resources, one that may force the government to make a hard choice: either build costly proposed south-north water diversion projects or battle the advancing deserts that are marching eastward and could eventually occupy Beijing.

Wang Hongchang, Deforestation and Desiccation in China: A Preliminary Study (Beijing, China: Center for Environment and Development, Chinese Academy of Social Sciences), 1999.

Wang Tao, The Process and Its Control of Sandy Desertification in Northern China, seminar on desertification in China, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences (Lanzhou, China: May 2002).

U.S. Embassy, Grapes of Wrath in Inner Mongolia (Beijing: May 2001).

Hong Yang and Xiubin Li, "Cultivated Land and Food Supply in China," Land Use Policy, vol. 17, no. 2 (2000).